#include<stdio.h>
#include<stdlib.h>


typedef struct binarytree
{
	int data;
	struct binarytree *lchild;
	struct binarytree *parent;
	struct binarytree *rchild;
}BT;

BT * init_bt()
{
	BT *tree=(BT *)malloc(sizeof(BT));
	tree->parent=NULL;
	tree->lchild=NULL;
	tree->rchild=NULL;
	return tree;
}

bool insert_child(BT *p,bool leftchild,int value)
{
	if(p)
	{
		BT *node=(BT *)malloc(sizeof(BT));
		node->parent=p;
		node->lchild=NULL;
		node->rchild=NULL;
		node->data=value;
		if(leftchild) p->lchild=node;
		else p->rchild=node;
	}
	else return false;
	return true;
}


void visit(BT *p)
{
	if(p) printf("%d ",p->data);
}


void pre_oder(BT *root)
{
	if(root) visit(root);
	if(root->lchild) pre_oder(root->lchild);
	if(root->rchild) pre_oder(root->rchild);
}



void destroy_tree( BT *root)
{
	if(root)
	{
		if(root->lchild) destroy_tree(root->lchild);
		if(root->rchild) destroy_tree(root->rchild);
		free(root);
	}
}

int main(){


	BT *root;
	root=init_bt();
	root->data=1;
	insert_child(root,1,2);
	insert_child(root,0,3);
	insert_child(root->lchild,1,4);
	insert_child(root->lchild,0,5);
	insert_child(root->rchild,0,6);
	pre_oder(root);
	destroy_tree(root);
	system("pause");
	
}